Supertech Performance TEVN-1083F Black Nitrided Exhaust Valve Toyota Oversize - 1.5mm

The Supertech Performance TEVN-1083F is a Black Nitrided stainless steel exhaust valve engineered for Toyota engines, offered in a +1.5mm oversize head diameter. Backed by over 30 years of racing valve manufacturing experience, Supertech designs each valve to deliver superior flow, durability, and reliability for both street performance and race engine builds.

Construction & Materials:

• One-Piece Forged EV8 (21-4N) Stainless Steel — The single-piece forging process eliminates weak joints and delivers higher tensile strength and fatigue resistance compared to multi-piece alternatives.
• Black Nitride Coating — A thermochemical hardening treatment that produces a microhardness of 800HV minimum, a smoother stem surface than chrome-plated valves, and significantly reduced friction between the valve stem and guide for extended service life.
• +1.5mm Oversize Head Diameter — The enlarged valve head increases the port's effective flow area, improving cylinder filling efficiency, particularly at lower valve lifts. Note: oversize valves require machining of existing valve seats or installation of aftermarket valve seats prior to installation.

Key Features:

• Forged one-piece EV8 (21-4N) stainless steel construction
• Black Nitride surface treatment for reduced stem-to-guide friction and improved wear resistance
• +1.5mm oversize head diameter for increased exhaust flow
• Application-specific heat treatment for optimal hardness and ductility balance
• Engineered for high-RPM, boosted, and performance street/race applications

Sold individually (per valve). Order the exact quantity required for your engine build — for example, a 12-valve engine requires a quantity of 12. Oversized valves are not a direct drop-in replacement and require valve seat machining or aftermarket valve seats.